Conventional videoconferencing systems include a number of end-points communicating real-time video, audio and/or data (often referred to as duo video) streams over and between various networks such as WAN, LAN and circuit switched networks.
A number of videoconference systems residing at different sites may participate in the same conference, most often, through one or more Multipoint Control Units (MCUs) performing switching and mixing functions to allow the audiovisual terminals to intercommunicate properly.
However, representing moving pictures requires bulk information as digital video typically described by representing each pixel in a picture with 8 bits (1 Byte). Such uncompressed video data results in large bit volumes, which is difficult to transfer over conventional communication networks and transmission lines in real time due to limited bandwidth.
Thus, enabling real time video transmission requires a large extent of data compression which may compromise picture quality. The compression of multimedia data to be transmitted, as well as the decompression of the multimedia data to be received, takes place in a processor unit conventionally referred to as a codec.
As videoconferencing involves various recourses and equipment simultaneously interoperating at different localizations and capabilities, there is also a need for the possibility to manage the resources involved both for scheduled and ad hoc videoconferences through a video conference manager tool.
Video conferencing systems provide communication between at least two locations for allowing a video conference among participants situated at each location. Conventionally, the video conferencing arrangements are provided with one or more cameras. The outputs of those cameras are transmitted along with audio signals to a corresponding plurality of displays at a second location such that the participants at the first location are perceived to be present or face-to-face with participants at the second location.
Further, the images captured by the plurality of cameras must be arranged and displayed so that they generate a non-overlapping and/or contiguous field of view, so-called continuous presence. Continuous presence is a mixed picture created from far-end sites in an MCU. For example, in case of a videoconference of five participants, each site will receive a picture divided into four quadrants with the picture captured from each of the other sites inserted in respective quadrants.
Continuous presence or several displays with only one camera prevents the feeling of eye-contact among participants in video conferencing systems. Typically, a camera is placed somewhere above the display at which a participant is observing a display of the participant from the remote station. Consequently, the camera captures the participant at an angle above and on the side of the participants viewing level or head. Thus, when an image of that participant is displayed at the remote station, it appears as if the participant is looking down or to the left or right. Previous solutions to this problem have required complex optical systems and methods using, for example, a plurality of lenses and mirrors. The solutions have usually been designed for use when the camera is capturing an image of a single participant, and they fall short when simultaneously capturing images of multiple participants.
In addition to the lack of sufficient eye-contact, there are also other limitations in conventional videoconferencing limiting the feeling of being in the same room. Continuous presence and small displays also limit the size of the displayed participants. Low capturing and display resolution and highly compressed data also contribute to a reduction of the experience of presence. Some solutions have tried to improve this by introducing so-called telepresence systems requiring dedicated high bandwidth communication lines. However, these solutions are not well suited to be connected to a conventional LAN or WLAN, and are not interoperable with conventional videoconferencing systems.
U.S. 2008/0246834 A1 (U.S. application Ser. No. 12/050,004, filed on Mar. 17, 2008) describes a communication system which addresses these issues, wherein at least two telepresence terminals, each terminal having at least one transceiver, are connected by more than one separate point-to-point connection between the separate transceivers of each of the telepresence terminals. Which transceiver in which endpoints to connect to each other, are set up when a conference is established, e.g., on a request from a control unit or from a conference manager, a master site starts transmitting instructions to the other participating telepresence systems on how to set up connections between them. The instructions are sent to the master transceiver, which in turn relays the instructions to the other transceivers in question. The instructions are typically incorporated in an open field in the message flow specifying the control protocol of establishing video conference call, such as ITU H.241, H.242 or H.243. Previous instructions schemes have been unreliable, and as such there is a need in the art of an improved method and system of establishing telepresence conference calls. U.S. 2008/0246834 A1 is incorporated in its entirety herein by reference.